Chemists advance development of marijuana breathalyzer

A group of academicians devised a method to detect marijuana with a breath analyzer, similar to how an alcohol analyzer detects the presence of alcohol in one’s body through the breath. They are usually used by police to determine if someone is breaking the law by driving while inebriated.

Professor of organic chemistry at UCLA Neil Garg and researchers from the UCLA start-up ElectraTect Inc. describe the method by which THC introduced in a solution into their laboratory-built device can be oxidised, producing an electric current whose strength indicates how much of the psychoactive compound is present.

The research was published in the journal Organic Letters. According to the researchers, the availability of a Breathalyzer-like device could contribute to making roads safer given the recent legalisation or decriminalisation of marijuana in numerous jurisdictions, including California. Marijuana use has been linked to dramatically increased accident risk and has been demonstrated to impair some driving abilities.

In 2020, Garg and UCLA postdoctoral researcher Evan Darzi observed that the bigger THC molecule had a visible colour change when a hydrogen molecule was removed from it. The method, called oxidation, is comparable to how alcohol breath analyzers turn ethanol into an organic chemical molecule by losing hydrogen. This oxidation results in an electric current in the majority of modern alcohol breath analyzer systems, which displays the quantity and concentration of ethanol in the breath.

Since their discovery in 2020, the researchers have been working on creating a THC breath analyzer that functions similarly using their patent-pending oxidation method. The patent rights have been leased exclusively to ElectraTect by UCLA.

How the new device works

Darzi, who is currently the CEO of ElectraTect, Garg, and researchers from ElectraTect describe the operation of their brand-new laboratory-scale THC-powered fuel cell sensor in the new study. THC (technically known as Delta-9-tetrahydrocannabinol) oxidises into a new compound called THCQ when it comes into contact with a negatively charged electrode, or anode, on one side of the device’s H-shaped glass chamber, sending electrons across the chamber to a positively charged electrode, or cathode, on the other, creating a detectable electric current. The current becomes stronger as the amount of THC molecules increases.

THC has never before been utilised to operate a fuel cell sensor, so this development is significant. Researchers are currently working to refine the device to detect and measure THC in exhaled breath and to shrink it to a more compact size suitable for use in a handheld breath analyzer or ignition interlock device–a breath analyzer connected to a vehicle’s ignition that prevents it from starting if THC is detected. The researchers said they expect that the relatively simple, inexpensive technology, once perfected, can be scaled up for economical mass production.

Making marijuana testing easier – and fairer

The technology may also result in increased road safety and more equitable marijuana law enforcement, according to the researchers. THC usage in drivers is typically detected through urine or blood tests. Such roadside tests can be challenging to do, and they aren’t always reliable for detecting intoxicated drivers because the chemical can persist in the body for weeks after marijuana use without having any lasting impact on cognition. Even if a person doesn’t test positive for drugs when tested, this ambiguity might result in penalties, jail time, or loss of work.

These problems, according to the researchers, emphasise the requirement for cutting-edge forensic technology that are simpler to use and more precise for identifying recent marijuana use. Although a commercial marijuana breathalyser based on their research would be a few years away, Darzi and Garg emphasised that such a device would potentially offer advantages beyond those of law enforcement and traffic safety.

Their scientific advancement, they claimed, could eventually be applied in any circumstance where unbiased marijuana testing is necessary, such as at work where employees might be operating machinery or even at home where people might one day be able to use it proactively — before they ever get behind the wheel.

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